Speaker
Description
Europa hosts a periodically changing plasma interaction driven by the spatial variations of Jupiter's magnetic field and magnetospheric plasma. We have developed a multi-fluid magnetohydrodynamic (MHD) model for the plasma interaction to investigate its response to these magnetic field and plasma variations at Europa's orbit. The model solves the multi-fluid MHD equations for electrons and three ion fluids (magnetospheric O+ as well as O+ and O+2 of ionospheric origin) while incorporating sources and losses in the fluid equations due to ionization, recombination, charge exchange and other relevant collisional effects. We first verify the accuracy of our model's representation of the plasma interaction by simulating the Galileo E4 flyby using input parameters constrained by the Galileo MAG and PLS observations. Our model produces 3D magnetic field and plasma bulk parameters that agree with and provide context for the E4 flyby observations. We next present the results of a parameter study of Europa's plasma interaction at three different S-III longitudes within the magnetosphere, for three different global magnetospheric states, comprising 9 steady-state simulations in total. We describe how the self-consistently generated ionosphere varies in response to the external plasma, and we show how the relative strengths of the magnetospheric plasma versus Europa’s ionosphere control Europa's interaction with Jupiter's magnetosphere.
